Piano action



C. KOEHLER 'Oct. 27, 1925. 1,558,817

PIANO ACTION Filed July 9, 1923 6;? i M %A RNEYL/ Patented Oct. 27,1925.

UNITED STATES 1,558,817 PATENT OFFICE.

CHARLES KOEHLER, or CHICAGO, ILLINOIS.

PIANO Application filed July 9,

To all whom it may concern:

x Be it known that I, CHARLES Konrinnn, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Piano Actions, of whichthe following is a specification.

This invention has to do with certain improvements in piano actinsthatis, the mechanism for transferring the movement of the finger key of thepiano to the hammer or striker.

One object of the invention is to provide an arrangement whereby themovement of the key is transferred to the hammer by an arrangement ofparts which eliminates the necessity of using expensive materials suchas buck-skin or specially prepared leather on the surfacesof certain ofthe parts which come into contact. In this connection, it has beencustomary in the past to face certain of the parts with leather ofsuitable nature, so that the proper action will be given both during theoperation of transferring movement to the hammer and the furtheroperation of disengaging the parts so that the hammer will strikefreely. This leather, so

used in the past, is expensive and requires great care and skill inplacing it on the parts so as to secure the proper action.

According to the present invention I have provided anarrangement wherebythe movement is transmitted between the parts by the use of silken cordsor bands and without the necessity of using this specially characterized leather. At the same time I have pro- Vided an arrangement' wherebythe action itself is very greatly improved and whereby the cost ofconstruction is considerably lowered and the touch made much lighter.

A further feature of the invention relates to the provision of animproved means whereby the action may be very easily adjusted so as tosecure proper striking of the hammer with the desired lightness oftouch. According to this feature of the present invention, the exactposition of the hammer at which the same is disengaged from the keylever may be easily adjusted so as to ensure accurate hammer movementcombined with lightness of touch and proper recoil.

A further object of the invention is to combine all of the foregoingfeatures in an arrangement of simple construction and great durabilityand which can be cheaply manufactured and assembled,

ACTION.

1923. Serial No. 650,380.

Other objects and uses of the invention will appear from a detaileddescription of the same which consists in the features of constructionand combinations of parts hereinafter described and claimed.

In the drawing:

Fig. 1 shows avertical elevation of a piano action embodying thefeatures of the present invention, the same being shown in the positionwhich the parts occupy with respect to the piano frame when the hammeris at rest, the finger key beingbroken away so as to shorten up thefigure;

Fig. 2 shows a perspective view of the butt on the lower end of thehammer. stem; and 1 Fig. 3 shows a perspective view of the upper portionof the operating trigger together with the cord which engages theaforesaid hammer butt.

In the construction illustrated in the drawing, the finger key isdesignated by the numeral 4. It is pivoted to the frame bar 5 on the pin6, and the rear end of the key lever 4 normally stands at rest against acushion of felt or the like 7 on the top surface of a frame bar 8. Apressure block 9 is threaded upon the upper end of a stem 10 on the rear4 end of the key lever 4 so that said pressure block can be raised andlowered for purposes of adjustment.

The cord or string is designated by the numeral 11. The hammer 12 ismade of felt or other appropriate material and is carried on the upperend of the hammer stem 13. Normally the hammer stem 13 rests against afelt or cushion facing 14 on the frame bar 15 as shown in Fig. 1.

The lower end of the hammer stem 13 is mounted within a hammer butt 16pivoted on the pin 17 which passes through a loop of metal strap 18secured to the frame bar 19. The arrangement is such that the hammerbutt 16 may oscillate perfectly. free on the pivotal point 17.

A wippen- 20 has its rear end articulated on the pivot point 21 carriedby the bracket lower surface of the wippen 20, and the cushposition toreceive the pressure from the block 9 and also fully protects theeushion-- ing block 23 at its ends, as well as in its central portion.

A jack 25 has its lower end pivoted at the point 26 to a bracket 27which reaches up.- wardly from the wippen 20. This jack 25 is preferablyof bell crank shape, as shown in Fig. 1, and a spring 28 is providedbetween the under surface of the short arm 29 of said bell crank and thetop surface of the wippen 20. This-spring, therefore, tends to tiltthe'jack rearwardly so as to carry its upper portion 30 towards thehammer butt The hammer butt itself is preferably recessed in its lowerfront corners, as shown at 31 in Fig. 2, so as to establish a relativelynarrow vertically extending forwardly reaching tongue 32, as clearlyshown in said figure. This tongue is in turn slotted inwardly as shownat 33, said slot extending in a direction substantially at right anglesto the line of thrustof the jack 25' when thewippen 20vis raised. Theforward corner 34 of the tongue 32 is made relatively sharp at the uppersurface of the slot 33.

The, upper portion 3O of the jack 25' is bifurcated as shown at 35inFig.3 so as to establish the fingers 36and 37 which are of sufiicientseparation to receive the tongue between them. Also the depth of thebifurcated portion is suiiicient to cause the body portion of the jackto clear the tongueat all times.

Stretched between the upper ends of the fingers 36 and 37 is a cord 38'of suitable materialof, proper s'izeto work easily within the slot 33 ofthe tongue. This cord 38 may be of anyv suitable material, butexperience shows that silk is admirably adapted for use 'in the presentinvei'ition, and I, therefore,

prefer to use the same. As a matter of convenience in construction, ,Iprefer' to form a transverse slot 39 across the front face of theupperportion 3(l'of' the jack 25, so that the ends of the cord 38jcan becarried dolwn interposed into said slot 39 and there held in place asbymeans of he or the like 40; Located above the heel portion 29' of thejack is. a frame bar 41 into which isl-threaded a stem 42, the lower endof whioli' carries a block 43 preferably faced with felt or the like 44on its bottom surface. This block 43 can be raised and lowered .in' avery simple manner according to this constructionv i The hammer butt 16'carries ferwardly projectinggstein 45': on-the end of" which is a block,46' plifeiahly faeecl with: felt or the like 47'. A recoiibieck' 48 iscarriedbythe upper end of a stem 49011 the end portion of the wippen 20,said recoil block 48 being preferably surfaced with felt or' the like 50in positionrto contact against the felt surface 47 of the block 46. 5

The block 46 has a finger 51 on its lower end which is preferablysurfaced with a block off'elt or the like 52, and the upper portion 30of the jack 25 is preferably provided with a cushioning block 53 of feltor the like in position to engage'tho block. 52 just above referred to.V erably so arranged that the block 53 overlies the slot39 in the upperportion of the ack The operation of this device is as follows: Uponquickly depressing akey lever 4, its rear end will rise so as to movethe wippen 20' upwardly. The jack '25 will thus be forced up and thecord 38 will act upon the tongue of the hammer butt 16 so as to commencethe striking movement of the'hammer. The engagement of the cord 38 withThe parts are pref-- the tongue 32will continue until the heel 29engages the knock off surface 44 of the'block 43 on the stem 42 and theposition of such engagement can be readily adjusted by threading thestem up or down.

M As soon as the heel 29- engages the stop just referred to, any furtherrise of the wippen 20 will not only'continu'e to throw the hammertowards the string ll, but will cause the jack 25 to swing away from theblock 16, so that the cord 38 will very quickly ride from under thecorner 34 of'the' tongue 32. Instantly that this takes place, the armandjack are completely disengaged, and the further throw of the hammeris dependent entirely upon its previously acquired momentum.

Further rise of the wippen 20 carries the recoil block 48 towards thehammer butt 16 andin'to position to receive impact from the block 46which extendsiearwardly from the hammer butt 16. Consequently the recoilblock 48 stands in posit-ion'to takethe recoil of the hammer andcushionsame as soon as the hammer flies back from the string 11. The. forwardmovement ofthe wippen 20 and associated parts is limited by engage- I rment ofthe' stem 49 with thefraine bar 41. at the sides of the fingers36 and 37' and f l cord'3'8 of the jack 25 will be caused to hook As thewippen 20 drops downwardly the only a single embodiment of thefeaturesiof my" invention, stillI do not limit myself to the same exceptas I may do so'iirthe claims.

I claim:

1. A piano action comprising in combination a hammer, a hammer stemtherefor, a hammer butt, a pivotal mounting therefor, the lower portionof said hammer butt having a relatively narrow tongue, a wippen pivotedbeneath the position of the hammer butt, a jack pivoted to said wippenand having its upper end bifurcated and adapted to receive the tongue ofthe hammer butt, there being an inwardly reaching slot in said tongue, acord between the bifurcations of the jack adapted to engage said slot, asidewise projecting heel on the jack, a stop on said heel. for limitingits upward movement, and means for adjusting the elevation of said stopwith respect to the wippen substantially as described.

2. A piano action comprising in combination a hammer butt, a hammerconnected thereto, a pivotal mounting for the hammer butt, a relativelynarrow tongue on the hammer butt, there being an inwardly reaching slotin said tongue, a wippen pivoted beneath the position of the hammerbutt, a jack pivotally mounted upon said wippen, the upper portion ofsaid jack being bifurcated, a cord extending between the bifurcationsand adapted to enga e the slot of the tongue, there being a sidewiseprojecting heel on the tongue, and means for limiting the upwardmovement of said heel, substantially as described.

3. In a piano action, the combination of a hammer butt, a pivotalmounting therefor, an inwardly reaching transverse slot in said hammerbutt, a wippen pivoted beneath the position of the hammer butt, a jackpivotally mounted upon said wippen, the upper portion of said jack beingbifurcated, a cord extending between the bifurcations of the jack andadapted to engage the slot of the hammer butt, and means for causing thejack to swing away from the hammer butt at a predetermined position inits upward movement, substantially as described.

4. In a piano action, the combination of a hammer butt, a pivotalmounting therefor, there being a transverse inwardly extending slot inthe hammer butt, a jack having its upper portion bifurcated, a cordextending between the bifurcations of the jack, a pivotal mounting forthe ack, means for moving said pivotal mounting vertically, and meansfor swinging the jack on its pivotal mounting when said pivotal mountingreaches a predetermined elevation, substantially as described.

CHARLES KOEHLER.

